Method and arrangement of testing device mobile station

ABSTRACT

The invention relates to a method and an arrangement of testing a device, such as a peripheral device, in a mobile station. The arrangement comprises a signal generator for generating a test signal for the device under test, a measurement unit integrated into the mobile station for measuring en electric quantity from a feeding line of the device under test, and an analyser for determining an electric response of the device to the test signal by using the electric quantity. According to the invention, at least a portion of the testing procedure composed of generating the test signal and determining the electric response of the device is performed using a functional unit, such as the signal generator or the analyser, integrated into the mobile station.

FIELD

The invention relates to a method and an arrangement of testing a devicein a mobile station.

BACKGROUND

As the output of production lines manufacturing mobile stations, such asmobile phones, has increased, specific care has to be taken to improveperformance of the testing procedure and fault detection of the finalproduct. A substantial portion of the testing procedure is aimed attesting electrical components and peripheral devices, such as display,vibrating battery, audio interface and keyboard of a mobile station.

In prior art, the testing procedure of devices of mobile stations isbased on generating a test signal and determining the response of thedevice under test by using external test equipment, such as a signalgenerator and a signal analyser.

The problems with the prior art testing procedures are several. Usingexternal test equipment requires a complicated and expensive set ofelectronic and mechanical devices and necessitates accurate placement ofthe mobile station to the test platform in order to obtain a physicalcoupling, such as galvanic connection, between the external testequipment and the mobile station. The physical connection between theexternal test equipment and the mobile station is prone to failures,thus reducing reliability of the test.

BRIEF DESCRIPTION OF THE INVENTION

An object of the invention is to provide an improved method andarrangement of testing a device in a mobile station. According to anaspect of the invention, there is provided a method of testing a deviceof a mobile station, the method comprising: generating an electric testsignal for testing a device, feeding the electric test signal to thedevice by a feeding line; measuring an electric quantity from thefeeding line by a measurement unit integrated into the mobile station;determining an electric response of the device to the electric testsignal based on the electric quantity; and performing at least theportion of a testing procedure by using a functional unit integratedinto the mobile station, the testing procedure comprising generating theelectric test signal and determining the electric response of thedevice.

According to another aspect of the invention, there is provided anarrangement for testing a device of a mobile station, comprising: asignal generator for generating an electric test signal for testing adevice; a feeding line connected to the signal generator and the devicefor feeding the electric test signal to the device; and the mobilestation further comprises a measurement unit connected to the feedingline for measuring an electric quantity from the feeding line; themobile station further comprises an analyser connected to themeasurement unit for determining an electric response of the device tothe electric test signal based on the electric quantity; and at least aportion of a testing arrangement is integrated into the mobile station,the testing arrangement comprising the signal generator and theanalyser.

Preferred embodiments of the invention are described in the dependentclaims.

The method and system of the invention provide several advantages. In anaspect, the invention reduces the need for external test equipment, thusdecreasing the cost of a test line, simplifying the testing procedureand increasing the output and reliability of a test line in massproduction of mobile stations.

LIST OF DRAWINGS

In the following, the invention will be described in greater detail withreference to the preferred embodiments and the accompanying drawings, inwhich

FIG. 1 shows an example of the structure of a mobile station by means ofa block diagram,

FIG. 2 shows an example of an arrangement for testing a device of amobile station by means of a block diagram;

FIG. 3 shows an example of an arrangement for testing an audio device ofa mobile station, and

FIG. 4 shows a flow chart illustrating embodiments of the invention.

DESCRIPTION OF EMBODIMENTS

FIG. 1 shows an example of the structure of a mobile station 100 bymeans of a block diagram. The mobile station 100 comprises a base bandpart (BB) 104 and a radio frequency part (RF) 102 placed, for example,on a printed circuit board 120.

The base band part 104 comprises a system block (SYST) 112 and a mixedsignal block (MXS) 114 connected to the system block 112. The systemblock 112 includes, for example, a digital signal processor (DSP) andmemory means, such as a static random access memory (SRAM) and aread-only memory (ROM).

The mixed signal block 114 includes, for example, analogue-to-digitaland digital-to-analogue converters for the payload signal transmittedand received by the mobile station 100.

The radio frequency part 102 comprises a radio frequency applicationspecific circuit (RF ASIC) 106, an amplifier unit (AMP) 108 and anantenna unit (ANT) 110.

The radio frequency ASIC 106 comprises, for example, converters forup-converting the base band signals to radio frequency band anddown-converting signals on the radio frequency band to base band.

The amplifier unit 108 comprises, for example, power amplifiers foramplifying low-power signals from the radio frequency ASIC 106 andfeeding the amplified signals to the antenna unit 110.

Furthermore, the amplifier unit 108 may comprise a low-noise amplifierfor amplifying a signal received from the antenna unit 110.

The antenna unit 110 comprises at least one antenna element forimplementing the radio interface between the mobile station 100 and anetwork. The antenna unit 110 may also include a filter means, such as aduplex filter, for filtering signals transmitted and received by theantenna unit 110.

The mobile station 100 comprises a peripheral device, which can beintegrated into the mobile station 100, or which can be external to themobile station 100.

FIG. 1 shows the following peripheral devices of the mobile station 100:a camera 130, an auxiliary radio transceiver 132, an optical port 134,an earphone 136, a microphone 146, a vibrator 138, a battery 140, abackup unit 142, a charger 144, a buzzer 148, a display 150, apositioning device 152, a keyboard 154, and a sensor 156.

The camera 130 may be a digital camera integrated into the mobilestation 100 or connected to the mobile station 100 via an auxiliaryport. In an embodiment, the camera 130 is a video camera connected tothe mobile station 100.

The auxiliary radio transceiver 132 may be, for example, a Blue Toothtransceiver for implementing a radio interface between an auxiliaryradio device, such as a Blue Tooth hands-free device, and the mobilestation 100.

The optical port 134 provides an optical bus for communication betweenthe mobile station 100 and an external device, such as another mobilestation or a computer equipped with an optical port and supporting acommon protocol. The optical port 134 comprises electro-opticalcomponents, such as diodes, for performing conversion between anelectric signal and an optical signal. In an embodiment, the opticalport 134 is an infrared port.

The earphone 136 and the microphone 146 compose an audio user interfacefor the mobile station 100. The earphone 136 converts an electricvibration into a voice vibration, and thus in general represents aloudspeaker. The earphone 136 may include a diaphragm connected to anelectric circuit transforming the electric signal into movement of thediaphragm.

The microphone 146 converts sound waves into electric signals. Themicrophone 146 may include a diaphragm connected to an electric circuitgenerating an electric signal from the vibration of the diaphragm. Theearphone 136 and the microphone 146 may be integrated into the mobilestation 100, or they can be external to the mobile station 100 connectedto the mobile station 100 by cables.

The vibrator 138 comprises an electric motor and mechanism for providinga vibrating alarm. The vibrator may be integrated into the battery ofthe mobile station 100.

The backup unit 142 comprises memory components for storing, forexample, time information, while power from the main power source, suchas a battery, is not available. The charger 144 provides power forcharging a battery of the mobile station 100. The charger usuallycomprises a transformer for transforming, for example, distributionvoltage to battery voltage. Also, the charger may comprise a rectifierfor converting alternating current to direct current.

The buzzer 148 provides sound effects in a narrow frequency band forinforming, for example, about an incoming call or a message. The buzzer148 may comprise a piezoelectric element for sound production.

The display 150 provides a visual user interface. The display 150 maycomprise an LCD (Liquid Crystal Device) for transforming an electricsignal to an optical image.

The positioning device 152 provides position information and possiblyreference time for the mobile station 100. The positioning device may beimplemented in the mobile station 100, or it can be an external device.In an embodiment, the positioning device 152 is a GPS (globalpositioning system) terminal.

The keyboard 154 comprises switches for converting a mechanical movementinto a change in electric conductivity. Furthermore, the keyboard 154may comprise illuminating means, such as diodes, for illuminatingbackground of the keyboard 154.

The sensor 156 may measure physical quantities, such as temperature,pressure, acceleration, humidity, and illumination. The sensor 156 mayinclude, for example, temperature sensitive resistors, film capacitors,and light diodes.

The invention is related to testing a device of a mobile station 100. Adevice, in general, may be an electric component or a functional entitycomposed of electric components. An electric component may be aresistor, a capacitor, a coil, an amplifier, a transistor, a diode, amemory circuit or a combination thereof. The device may also be anintegrated circuit or a portion of an integrated circuit. The device tobe tested may be located anywhere in the mobile station.

FIG. 1 shows an exemplified structure of a mobile station 100, and thedetails and implementation of the base band part 102 and the radiofrequency part 102 may vary in many ways. In this example, theperipheral devices 130-156 are connected to the base band part 104. Theimplementation of the connection between a peripheral device 130-156 andthe base band part 104 may vary depending on the layout of theelectronics in the mobile station 100. In an embodiment, a peripheraldevice 130-156 is connected to the mixed signal block 114.

FIG. 2 shows an example of an arrangement for testing a device of amobile station 100 at a block diagram level. FIG. 2 shows devices 200,202, 204 to be tested, a signal generator 230, feeding lines 210, 212and 214 connected to the devices 200, 202, and 204, respectively, andthe signal generator 230, a measurement unit 250 connected to thefeeding line 210, 212, 214, and an analyser 260 connected to themeasurement unit 250.

FIG. 2 also shows an external test system 290. The external test system290 is located outside the mobile station and includes, for example, acomputer and memory means. The external test system 290 may be, forexample, a portion of a production line test system, or a portion of atest system used in mobile station service. The external test system290, for example, transmits a command 286 for launching a testingprocedure for testing the device 200, 202, 204, and receives a reportsignal 272 concerning the testing results.

The signal generator 230 generates an electric test signal for testingthe device 200, 202, 204, which test signal is fed to the device 200,202, 204 by the feeding line 210, 212, 214. The feeding line 210, 212,214 may be, for example, a power supply line providing the device 200,202, 204 with operating voltage, a control line providing the device200, 202, 204 with a control signal, an input line providing the device200, 202, 204 with a payload input signal, or an output signal lineproviding an output payload signal from the device 200, 202, 204. Theinput line, for example, delivers an audio signal to the earphone 136 ofthe mobile station 100. The output signal line, for example, outputs anaudio signal from the microphone 146 of the mobile station 100.

In an aspect of the invention, at least a portion of the testarrangement comprising the signal generator 230 and the analyser 260 isintegrated into the mobile station such that at least a portion of atesting procedure comprising generating the electric test signal anddetermining electric response of the device may be performed by using afunctional unit integrated into the mobile station 100. The integratedstructure relating to the generator 230 and the analyser 260 results insimplification of the test procedure and reduction in external testequipment, such as an external signal generator or a signal analyser.The simplification in the test procedure and the reduction in theexternal test equipment enables improvement in the output of the testline in mass production and reduced manufacturing costs.

In an embodiment, at least a portion of the signal generator 230 isintegrated into the mobile station 100. In this case, the portion of thesignal generator 230 represents the portion of the functional unit. Thedigital functions, such as generating the digital form of the testsignal, of the signal generator 230 may be implemented in the base bandpart 104, for example using the digital signal processor and software ofthe system block 112. When at least a portion of the signal generator230 is integrated into the mobile station 100, the analyser 260 may beexternal to the mobile station 100, or integrated at least partiallyinto the mobile station 100. The test signal may be a signal dedicatedto testing the device 200, 202, 204, or the test signal may be a genericsignal used in the normal operation of the device 200, 202, 204.

In an embodiment, the test signal is characterized by predefinedcharacteristics, such as voltage, current, frequency and a pulsesequence. The predefined characteristics may be defined by requirementsset by the device 200, 202, 204 and possibly the measurement unit 250.

In an embodiment, the feeding line 210, 212, 214 is implemented byforming a trace on a semiconductor board, such as a silicon board. Thefeeding line 210, 212, 214 may also be implemented by using conventionalcabling techniques known to a person skilled in the art.

An electric quantity is measured from the feeding line 210, 212, 214 bythe measurement unit 250 integrated into the mobile station 100. Theelectric quantity may be current or voltage, for example. In anembodiment, the measurement unit 250 generates a voltage 252proportional to the electrical quantity, which voltage represents themeasurement result.

The measurement unit 250 outputs the measurement result into an input ofthe analyser 260, which determines the electric response of the device200, 202, 204 to the electric test signal based on voltage. In anembodiment, the measurement result is conveyed by an analogue signal252, in which the measurement result is presented, for example, by avoltage level. In another embodiment, the measurement result is conveyedto the analyser 260 by a digital signal 252, which contains themeasurement result in a numeric form. For example, the measurement unit250 measures the voltage of the electric test signal over the device200, 202, 204, generates a voltage proportional to the measurementvoltage, inputs the voltage to the analyser 260, which determines theelectric response of the device 200, 202, 204 to the electric testsignal based on the voltage proportional to the measurement voltage. Forexample, resistive properties of the device 200, 202, 204 may be testedby feeding a DC current to the device and monitoring voltage over thedevice 200, 202, 204 by the measurement unit 250.

The measurement unit 250 may be integrated into the mobile station 100in various manners. In an embodiment, the measurement unit 250 isimplemented in the base band part 104, for example, by forming therequired component structure on a semiconductor board.

The integrity of the mobile station 100 and the measurement unit 250enables scanning the device 200, 202, 204 using internal structures ofthe mobile station 100, thus reducing the need for accessing the feedingline 210, 212, 214 from outside the mobile station 100. Theaccessibility of the feeding lines 210, 212, 214 and the device 200,202, 204 from outside a mobile station is, in general, difficult due tosmall dimensions of the electronics in a mobile station 100.

The electric response of the device 200, 202, 204 to the test signalcharacterises the functionality of the device. The electric response maybe, for example, the power consumption of the device 200, 202, 204,which can be deduced from the current through the device 200, 202, 204and the voltage applied over the device 200, 202, 204. In an embodiment,the electric response is the phase difference between the test signaland the electric quantity being measured. The phase difference may arisefrom, for example, impedance of components in the device 200, 202, 204.The electric response may also be a curve representing the electricquantity as a function of time, for example, when a capacitive device istested. In an embodiment, the feeding line 210, 212, 214 comprises ameasurement branch 220, 222, 224 for enabling remote measurement of theelectric quantity from the feeding line 210, 212, 214. The measurementbranch 220, 222, 224 provides sense lines to the measurement unit 240,thus enabling freedom, for example, in locating the measurement unit 240in the mobile station 100 and possibly in an ASIC on which themeasurement unit 250 is planted. In an embodiment, the measurementbranch 220, 222, 224 is located at the device end of the feeding line210, 212, 214 so that the effect of the electric response, such asresistance or impedance, of the feeding line 210, 212, 214 to themeasurement of the electrical quantity is reduced. Locating themeasurement branch 220, 222, 224 in the proximity of the device 200,202, 204 results in reduced effects from the portion of the feeding line210, 212, 214 between the measurement branch 220, 222, 224 and thedevice 200, 202, 204 to the electric response of the device 200, 202,204 to the test signal. For example, the feeding line 210, 212, 214 maygenerate voltage drops to the test due to interconnecting cables andtraces, which voltage drop is accounted for in the measurement of theelectric quantity if the voltage drop occurs between the measurementbranch 220, 222, 224 and the device 200, 202, 204. If the measurementbranch 220, 222, 224 is located such that the voltage drop occursbetween the measurement branch 220, 222, 224 and the generator 230, theeffect of the voltage drop is not accounted for in the measurement ofthe electric quantity, and the measurement provides more realisticcharacterization for the device 200, 202, 204. Locating the measurementbranch 220, 222, 224 in the proximity of the device 200, 202, 204corresponds to isolating sense lines providing the measurement signalfor the measurement unit 250 from the force lines providing the device200, 202, 204 with the electric test signal. The separation enablesmeasuring small impedances from the device 200, 202, 204. Themeasurement branch 220, 222, 224 may be implemented in a similar mannerto the feeding line 210, 212, 214.

In an embodiment, an input impedance of the measurement unit 250 ischosen such that the accuracy of the electric response of the device200, 202, 204 to the electric test signal is above a predefined value.The input impedance of the measurement unit 250 results in currentthrough the measurement unit 250, which current disturbs the measurementof the electric quantity, such as voltage, from the feeding line 210,212, 214.

The high impedance of the measurement unit 250 combined with locatingthe measurement branch 220, 222, 224 in the proximity of the device 200,202, 204 may also be called a Kelvin arrangement for measuring anelectric quantity from the feeding line 210, 212, 214. The Kelvinarrangement enables performing a measurement on the device 200, 202, 204with a small effect of the measurement circuit on the measurement. TheKelvin arrangement enables, for example, an accurate measurement on alow impedance device 200, 202, 204. The high impedance of themeasurement unit 250 may be defined in terms of the impedance of thedevice 200, 202, 204 under test. In an embodiment, the impedance ratior=Z_(meas)/Z_(device) is about 10000, where Z_(meas) is the impedance ofthe measurement circuit and Z_(device) is the impedance of the device200, 202, 204 under test.

In an embodiment, the input impedance of the measurement unit 250 mayrange between 1 MΩ and 10 MΩ. However, the invention is not restrictedto the above values, but the impedance of the measurement unit may behigher than 10 MΩ.

The analyser 260 receives a signal 252 carrying the measurement resultsof the electric quantity measured by the measurement unit 250. In anembodiment, at least a portion of the analyser 260 is integrated intothe mobile station 100. In such a case, the portion of the analyser 260represents the portion of the functional unit. The analyser 260 may beimplemented in the base band part 104 using, for example, a digitalsignal processor and software. In an embodiment, the analyser 260receives a digital signal 252 representing the measurement result of theelectric quantity. The analyser 260 may process the digital signal 252,for example, by averaging, scaling, filtering, windowing or/and masking.In an embodiment, the signal generator 230 and the analyser 260 areintegrated into the mobile station 100 by using the implementationdescribed above.

In an embodiment, the mobile station comprises a switching unit 240 forconnecting the measurement unit 240 to the feeding line 210, 212, 214.The switching unit 240 may be connected directly or via the measurementbranch 220, 222, 224 to the feeding line 210, 212, 214. In anembodiment, the switching unit 240 is implemented with a transistorplanted on a semiconductor board. In an embodiment, the switching unit240 is a Kelvin switch with high impedance when the switching unit 240is in the connecting state.

The switching unit 240 may also be capable of connecting the measurementunit 250 to a feeding line of plurality of feeding lines 200, 202, 204one at a time. Thus, the output signal 242 from the switching unit 240represents an electric quantity from either of the devices 200, 202, 204under test. The arrangement enables using a single measurement unit 250,and a single setup of electronics for measuring several devices 200,202, 204.

The arrangement may also comprise several measurements units 250, eachof which is connected to a measurement-unit-specific switching unit 240and an analyser 260 for enabling simultaneous tests for several devices200, 202, 204 in the mobile station. The use of simultaneous testsreduces the testing time of each mobile station and improves the outputof a test line in mass production.

In an embodiment, the arrangement comprises an evaluating unit 270connected to the analyser 260 for evaluating the performance of thedevice 200, 202, 204, based on the electric response. The analyser 260transmits information 262 on the electric response to the evaluationunit 270. Furthermore, the analyser may transmit information 254 to theexternal test system. If the electric response of the device 200, 202,204 to the electric test signal fulfils requirements set for theelectric response, the testing result is positive. The testing resultsmay further be transmitted to the external test system 290.

In an embodiment, the evaluation unit 270 is integrated into the mobilestation 100 by using the base band part 104, for example.

If the signal generator 230 and the analyser 260 are integrated into themobile station 100, the mobile station 100 is capable of self-testingwithout external test equipment. The test procedure may be initialisedby the user or it can be controlled from the network to which the mobilestation is connected.

In an embodiment, a predefined electric test signal is generated by thesignal generator 230 for testing a device 200, 202, 204 with a knownelectric response to the predefined electric test signal, and theperformance of the device 200, 202, 204 is evaluated based on the knownelectric response and the electric response of the device 200, 202, 204to the electric test signal. For example, if a discharge curve ofvoltage of a capacitor to be tested is known, the corresponding curvecan be determined by charging the capacitor with a known voltage of thetest signal. A measured discharge curve can be compared with the knowncurve, and the performance of the capacitor can be evaluated from thecorrespondence between the two curves. A similar procedure can beapplied to other devices.

In an embodiment, the arrangement comprises a control unit 280 forcontrolling a test procedure for testing the device 210, 212, 214. Thecontrol unit 280 comprises, for example, a digital computer with memorymeans for processing and storing data associated with testing proceduresof devices in a mobile station. The control unit 280 may be implementedin a base band part 104 of the mobile station 104.

In an embodiment, the control unit 280 receives a test command 286 tolaunch a testing procedure to test a device 200, 202, 204. The command286 may be generated in the mobile station 100, based on a detected orassumed malfunction in a device 200, 202, 204 to be tested. It is alsopossible to receive the test command 286 from the external test system290 while testing the mobile station 100 during a manufacturing stage orduring service of the mobile station 100.

In an embodiment, the test command 286 is delivered to the mobilestation by using a radio interface of a telecommunication system. Thetest command 286 may be generated by remote service personnel located ina network of the telecommunication system, for example, on a regularbasis or based on an indication of a malfunction in the mobile station.Information on the test, such as information 254 from the analyser 260or information 272 from the evaluating unit 270, may be transmitted fromthe mobile station to the service personnel for a detailed analysis. Insuch a case, some of the tasks of the evaluating unit 270 may be locatedin the network of the telecommunication system.

Some of the tasks of the control unit 280 may also be performed in thenetwork. For example, the remote service personnel may specify detailsof the testing procedure, possibly based on an earlier analysis so thatdetails of a malfunction can be investigated. After the analysis, theuser of the mobile station may be informed about a need for deliveringthe mobile station for repair.

The control unit 280 may store data concerning characteristics of thetest signal. For example, each device to be tested 200, 202, 204 mayhave device-specific testing parameters controlling, for example, theduration, voltage level and current to be applied to the test signal.The characteristics may be transmitted to the generator 230 by using agenerator control signal 282. The switch position of the switching unit240 may be controlled by a switch control signal 284.

In an embodiment, the device 200, 202, 204 is a radio frequencycomponent, such as the amplifier unit 108, the RF ASIC 106 or theantenna unit 110 located in the radio frequency part 102. The electriccomponents to be tested in the units listed may be, for example, a poweramplifier, a low noise amplifier, an analogue-to-digital converter, adigital-to-analogue converter, a filter, a diode, or an antenna. If thedevice 200, 202, 204 is a radio frequency component, at least a portionof testing the elements, such as the generator 230, the measurement unit250, the feeding line 210, 212, 214, the switching unit, and theanalyser 260, may be located in the radio frequency part 102.

In an embodiment, the device 200, 202, 204 is a peripheral device130-156. The present solution provides an efficient testing method andarrangement for testing a peripheral device 130-156 since the proceduretests an electric response instead of a functional response of aperipheral device 130-156. The functional response means, for example,sound reproduction of an audio device, such as a microphone 146 or anearphone 136, when a test signal is directed at the device 130-156. Thefunctional response necessitates an external microphone/loudspeaker inorder to perform conversion between a sound wave and an electric signal.The efficiency of determining the electric response arises from variousfactors, such as tolerance to external disturbance, such as noise andvibration from the test line, and a reduced need for changing a testplatform between different tests. FIG. 3 shows an example of a testingarrangement for testing an earphone 300. The testing arrangementcomprises an audio codec 312, a switching unit 324, a measurement unit326, and an analogue-to-digital converter 328. The aforementionedelements may be implemented in a single application-specific integratedcircuit 310. The arrangement further comprises a signal generator 332and an analyser 334 implemented with a digital signal processor 330 ofthe system block 112 of the mobile station 100. The control unit 340 andthe evaluation unit 350 are also shown.

The signal generator 332 feeds a test signal 302 into the audio codec312, which comprises an amplifier 318 for amplifying the test signal 302and feeding the test signal 302 into the feeding line. The feeding linecomprises a first pole 314 and a second pole 316 for providing an inputand an output for the current associated with the test signal. Themeasurement branches 320 and 322 of the first pole 314 and the secondpole 316, respectively, are connected to the switching unit 324, whichfurther conducts the measurement branches 320, 322 to the measurementunit 326 when the switching unit 324 is turned on. The measurement unit326 determines voltage between the first pole 314 and the second pole316 and provides output voltage 323, 325 to the analogue-to-digitalconverter 328. The analogue-to-digital-converter 328 outputs the outputvoltage 323, 325 in digital form 336 to the analyser 334 for processing.The analyser 334 outputs the processing results, such as the average ofthe measurement result, to the evaluating unit 350 for evaluating theperformance of the headphone 300.

With reference to FIG. 4, embodiments of the invention are illustratedby means of a block diagram. In start 400, the method is started. In402, an electric test signal is generated. In 404, the electric testsignal is fed to a device 200, 202, 204. In 406, a measurement unit 406is connected to the feeding line 210, 212, 214 by a switching unit 240.In 408, an electric quantity, such as voltage, is measured from thefeeding line 210, 212, 214. In 410, electric response of the device 200,202, 204 to the electric test signal is determined by the analyser 260.In 412, performance of the device 200, 202, 204 is evaluated based onthe electric quantity. In 414, the method is stopped.

Even though the invention is described above with reference to anexample according to the accompanying drawings, it is clear that theinvention is not restricted thereto but can be modified in several wayswithin the scope of the appended claims.

1. A method of testing a device of a mobile station, the methodcomprising: generating an electric test signal for testing a device;feeding the electric test signal to the device by a feeding line;measuring an electric quantity from the feeding line by a measurementunit integrated into the mobile station; determining an electricresponse of the device to the electric test signal based on the electricquantity; and performing at least a portion of the testing procedure byusing a functional unit integrated into the mobile station, the testingprocedure comprising generating the electric test signal and determiningthe electric response of the device.
 2. The method of claim 1, furthercomprising evaluating performance of the device based on the electricresponse.
 3. The method of claim 1, further comprising connecting themeasurement unit to the feeding line.
 4. The method of claim 1, whereinthe step of generating the electric test signal comprises generating theelectric test signal by a signal generator integrated at least partiallyinto the mobile station.
 5. The method of claim 1, wherein determiningthe electric response further comprises determining the electricresponse of the device to the electric test signal by an analyserintegrated at least partially into the mobile station.
 6. The method ofclaim 1, further comprising: measuring the voltage of the electric testsignal over the device; and determining the electric response of thedevice to the electric test signal, based on the voltage.
 7. The methodof claim 1, further comprising: generating a predefined electric testsignal for testing a device with a known electric response to thepredefined electric test signal; and evaluating performance of thedevice based on the known electric response and the electric response ofthe device to the electric test signal.
 8. The method of claim 1,wherein the step of measuring comprises measuring the electric quantityby a measurement unit with an input impedance chosen such that theaccuracy of the electric response of the device to the electric testsignal is above a predefined value.
 9. The method of claim 1, furthercomprising connecting a measurement unit measuring the electric quantityto a feeding line of a device of plurality of devices; and measuring theelectric quantity from a feeding line of a device of plurality ofdevices.
 10. The method of claim 1, wherein the device is a peripheraldevice.
 11. An arrangement for testing a device of a mobile station,comprising: a signal generator for generating an electric test signalfor testing a device; a feeding line connected to the signal generatorand the device for feeding the electric test signal to the device; ameasurement unit connected to the feeding line, for measuring anelectric quantity from the feeding line; an analyser connected to themeasurement unit, for determining an electric response of the device tothe electric test signal based on the electric quantity; wherein atleast a portion of a testing arrangement is integrated into the mobilestation, the testing arrangement comprising the signal generator and theanalyser.
 12. The arrangement of claim 11, wherein the arrangementfurther comprises an evaluating unit connected to the analyser forevaluating performance of the device based on the electric response. 13.The arrangement of claim 11, wherein the mobile station comprises aswitching unit for connecting the measurement unit to the feeding line.14. The arrangement of claim 11, wherein at least a portion of thesignal generator is integrated into the mobile station.
 15. Thearrangement of claim 11, wherein at least a portion of the analyser isintegrated into the mobile station.
 16. The arrangement of claim 11,wherein the measurement unit is configured to measure voltage of theelectric test signal over the device; and wherein the analyser isconfigured to determine the electric response of the device to theelectric test signal, based on the voltage.
 17. The arrangement of claim11, wherein the signal generator is configured to generate a predefinedelectric test signal for testing a device with a known electric responseto the predefined electric test signal; and wherein the evaluating unitis configured to evaluate performance of the device based on the knownelectric response and the electric response of the device to theelectric test signal.
 18. The arrangement of claim 11, wherein an inputimpedance of the measurement unit is chosen such that the accuracy ofthe electric response of device to the electric test signal is above apredefined value.
 19. The arrangement of claim 11, wherein the mobilestation comprises a plurality of devices with a plurality of feedinglines; wherein the mobile station comprises a switching unit forconnecting the measurement unit to the feeding line of the device of aplurality of devices one at a time; and wherein the measurement unit isconfigured to measure the electric quantity from the feeding line of thedevice from a plurality of devices.
 20. The arrangement of claim 11,wherein the device is a peripheral device.